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Oncorhynchus keta
Oncorhynchus keta (''Chum salmon)' Kingdom: '''Animalia Phylum: Chordata Class: Actinopterygii Order: Salmoniformes Family: Salmonidae Genus: Oncorhynchus Species: Oncorhynchus keta Environment: milieu, climate zone, depth range, distribution range: Marine; freshwater; brackish; benthopelagic; anadromous; depth range 0 - 250 m, usually ? - 61 m. Temperate; 0°C - 24°C; 77°N - 42°N, 120°E - 105°W. Distribution: North Pacific: Korea , Japan, Okhotsk and Bering Sea, Arctic Alaska south to San Diego, California, USA. Asia: Iran. Size, weight, age: Max. length: 1 m, common length: 58 cm; weight: 15.9 kg; age: 7 years Short description: The body of the chum salmon is deeper than most salmonid species. In common with other species found in the Pacific, the anal fin has 12 to 20 rays, compared with a maximum of 12 in European species. Chum have an ocean coloration of silvery blue green with some indistinct spotting in a darker shade, and a rather paler belly. When they move into fresh water the color changes to dark olive green and the belly color deepens. When adults are near spawning, they have purple blotchy streaks near the caudal peduncle, darker towards the tail. Spawning males typically grow an elongated snout or kype, their lower fins become tipped with white and they have enlarged teeth. Some researchers speculate these characteristics are used to compete for mates. Biology: Inhabits ocean and coastal streams. Migrating fry form schools in estuaries, remain close to shore for a few months and finally disperse to enter the sea. Epipelagic. Juveniles and adults feed mainly on copepods, tunicates and euphausiids but also on pteropods, squid and small fishes. Adults cease feeding in freshwater. Males and females die after spawning. The catch is mostly canned but also sold fresh, dried-salted, smoked, and frozen. Eaten steamed, fried, broiled, boiled, microwaved, and baked. Utilized for caviar. Life cycle and mating behavior: Enters freshwater during advanced stage of sexual development and spawning occurs almost immediately. Spawning occurs at depths of ~3 meters, current speeds of ~20cm/sec. near the head waters over sand and pebbles at 4-11° C water temperature. At spawning time the female excavates a hole of around 1 meter diameter and 50 cm depth before spawning can occur. Nest building is done by the female by lying on one side and lashing its tail to displace the sand and silt on the river bed. The pair then settles in the nest, mouths gape, and with rapid vibration of the pair, eggs and milt are released. The female then covers the nest. Males are aggressive and may spawn with different females; females likewise may spawn with other males and therefore builds different nests. Adults die after a week. A fish spawns 700-7,000 eggs in two to three egg releases. Eggs are ~300-3,500 per spawn. Egg size is ~6.7 mm, water temp. is 8-10°C at 60 days before hatching. Larva size is around 16 mm. Come springtime the juveniles go to the ocean and come back 3-4 years later to their exact birthplace. This fish reaches maturity in 2-4 years. Larvae are found around the spawning site, Juveniles are found around the coast. Juveniles migrate to the ocean at ~27-45 mm during February at water temperatures around 4° C. Reproductive strategy: synchronous ovarian organization, determinate fecundity. Main reference: Page, L.M. and B.M. Burr, 2011. A field guide to freshwater fishes of North America north of Mexico. Boston : Houghton Mifflin Harcourt, 663p. IUCN Red List Status: Not Evaluated CITES: Not Evaluated CMS: Not Evaluated Threat to humans: Harmless Human uses: Fisheries: highly commercial; aquaculture: commercial; gamefish: yes; aquarium: public aquariums. Category:Salmonidae, Salmonids